[TowerTalk] Switching ladder line

[Ian White, G3SEK]

Jan Ditzian wrote:
>
>I am interested in remotely switching among multiple balanced lines (450
>ohm).  There are latching vacuum relays that I can use, but they cost
>from $9 to $15 each and are mostly spst.  I originally thought to use
>two
>relays per antenna, one spst on each side of the line.
>
>I would like to know whether one can switch balanced lines the way one
>might switch coaxial lines, by leaving one side common and switching
>only the other side.  This would, of course, mean that I would need only
>half
>the number of relays that I would need for switching both sides.
>

W6RCA uses normal DPDT relays to switch in various lengths of ladder-
line  to match his multiband doublet. See schematics and photographs at:
 
http://people.delphi.com/CecilMoore/mystery.htm 

73 from Ian G3SEK          Editor, 'The VHF/UHF DX Book'
                          'In Practice' columnist for RadCom (RSGB)
                           http://www.ifwtech.com/g3sek

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